## College Algebra (10th Edition)

$\left[\begin{array}{lll} 0 & 12 & -20\\ 4 & 8 & 24 \end{array}\right]$
If $k$ is a real number and $A$ is an $m$ by $n$ matrix, the matrix $kA$ is the $m$ by $n$ matrix formed by multiplying each entry $a_{ij}$ in $A$ by $k$. $4A=4\left[\begin{array}{lll} 0 & 3 & -5\\ 1 & 2 & 6 \end{array}\right]=\left[\begin{array}{lll} 4\cdot 0 & 4\cdot 3 & 4\cdot(-5)\\ 4\cdot 1 & 4\cdot 2 & 4\cdot 6 \end{array}\right]$ $=\left[\begin{array}{lll} 0 & 12 & -20\\ 4 & 8 & 24 \end{array}\right]$